index.css

.ai-ecology {
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
}
.ai-ecology-item {
  -webkit-box-flex: 1;
  -webkit-flex: 1;
          flex: 1;
  position: relative;
  padding-bottom: 50%;
}
.ai-ecology-main {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}
.ai-ecology-main-paddle {
  top: 50%;
  -webkit-transform: translateY(-50%);
          transform: translateY(-50%);
}
.ai-ecology-title,
.ai-ecology-intro {
  text-align: center;
  color: #fff;
}
.ai-ecology-title {
  margin-bottom: .5rem;
  padding: 0.2rem;
  line-height: 1;
  font-size: 1.7rem;
}
.ai-ecology-title-paddle {
  font-size: 2rem;
}
.ai-ecology-intro {
  line-height: 1;
  font-size: 1rem;
  color: #ccc;
  letter-spacing: 1px;
}
.ai-ecology-intro-paddle {
  font-size: 1rem;
  color: #fff;
  margin-bottom: 1.5rem;
}
.ai-ecology-mask {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(35, 35, 35, 0.75);
}
.ai-ecology-mask-paddle {
  background: #000000;
  opacity: 0.4;
}
.ai-ecology-icon {
  width: 3.75rem;
  height: 3.75rem;
  margin: 25% auto .875rem;
  background-size: contain;
}
.ai-ecology-btn {
  display: inline-block;
  font-size: 1.2rem;
  color: #fff;
  line-height: 3rem;
  background: rgba(0, 0, 0, 0.5);
  border: 1px solid #fff;
  border-radius: 100px;
}
.ai-ecology-btn-content {
  margin: 0 1rem;
}
.ai-ecology-btn-icon {
  width: 1.2rem;
  height: 1.2rem;
}